In a variety of manufacturing processes including, without limitation, halogenated hydrocarbon manufacturing processes, water may be present in the starting materials or formed during the reaction. In these processes, it may be desirable to separate the water from the process products, byproducts, and unreacted starting materials.
Additionally, in a number of technologies, such as electronics and semiconductor manufacturing, solvents may be used for drying manufactured parts. For the solvent to be re-usable, the water must first be removed.
Further, in refrigeration, air-conditioning, and freezing equipment, a refrigerant is used as the working fluid. Because these systems usually cannot be manufactured so as to totally exclude water from entering the final product, some water may mix with the working liquid in the equipment causing problems with the proper functioning of the equipment.
A number of methods have been developed in order to separate water from chemical mixtures. The known methods include the use of alkaline earth compounds, carbon molecular sieves, oleum, distillation, and membranes. Each of the known methods is disadvantageous in that these processes are inefficient or uneconomical. Also, water may be difficult to separate using these methods because water forms an azeotropic mixture with certain chemicals, such as some of the fluorinated hydrocarbons. Additionally, some drying methods result in undesirable side reactions between the drying agent and the material to be dried.
Many useful desiccants adsorb or absorb the fluid that is being dried as well as take up water from the fluid. This is exemplified in the adsorption of difluoromethane by 4 .ANG. molecular sieves as described in U.S. Pat. No. 5,347,822.
Therefore, a need exists for an effective water separation method that attempts to overcome the disadvantages of the prior art methods.